There are different types of hearts of palm. For example, canned hearts of palm contains 117 kilojoules per 100g (33 cals per oz). This means it is less fattening than the majority of vegetable or vegetable-based food.
Technically, 471900 (the k stands for kilo which means 1000).
However, when we talk about calories in everyday situations we are normally referring to kilocalories (which is why you might see it...